Sex-related differences of fatty acid-binding protein 4 and leptin levels in atrial fibrillation

AIMS

Adiposity plays a key role in the pathogenesis of atrial fibrillation (AF). Our aim was to study the sex differences in adipokines levels according to AF burden.

METHODS AND RESULTS

Two independent cohorts of patients were studied: (i) consecutive patients with AF undergoing catheter ablation (n = 217) and (ii) a control group (n = 105). (i) Adipokines, oxidative stress, indirect autonomic markers, and leucocytes mRNA levels were analysed; (ii) correlation between biomarkers was explored with heatmaps and Kendall correlation coefficients; and (iii) logistic regression and random forest model were used to determine predictors of AF recurrence after ablation. Our results showed that: (i) fatty acid-binding protein 4 (FABP4) and leptin levels were higher in women than in men in both cohorts (P < 0.01). In women, FABP4 levels were higher on AF cohort (20 ± 14 control, 29 ± 18 paroxysmal AF and 31 ± 17 ng/mL persistent AF; P < 0.01). In men, leptin levels were lower on AF cohort (22 ± 15 control, 13 ± 16 paroxysmal AF and 13 ± 11 ng/mL persistent AF; P < 0.01). (ii) In female with paroxysmal AF, there was a lower acetylcholinesterase and higher carbonic anhydrase levels with respect to men (P < 0.05). (iii) Adipokines have an important role on discriminate AF recurrence after ablation. In persistent AF, FABP4 was the best predictor of recurrence after ablation (1.067, 95% confidence interval 1-1.14; P = 0.046).

CONCLUSION

The major finding of the present study is the sex-based differences of FABP4 and leptin levels according to AF burden. These adipokines are associated with oxidative stress, inflammatory and autonomic indirect markers, indicating that they may play a role in AF perpetuation.

Gender-dependent regulation of FABP4 and leptin according to atrial fibrillation burden

Aims

Adiposity plays a key role in the pathogenesis of atrial fibrillation (AF). Its associated proteins are differentially released between male and female. FABP4 and leptin are mediators in adipose tissue-inflammatory effects. Our aim was to study their gender differential behavior on mechanisms associated with AF progression.

Methods and results

Two independent cohorts were analyzed: A) patients referred for AF catheter ablation (n=217) and patients with suspected coronary artery disease referred for a CT scan (without previous history of AF) (n=105). Protein levels were determined by multiplex fluorometric immunoassay. Gene mRNA expression was analyzed by real time polymerase chain reaction. Correlation between biomarkers was explored with heatmaps and Kendall correlation coefficients. Logistic regression and random forest model determined the best predictors of AF recurrence after catheter ablation. Our results showed: 1) a distinctive profile according to gender, with an increment of FABP4 levels in women (20±14, 29±18 and 31±17 ng/mL; p=0.007) and a decrease of leptin levels in men (22±15, 13±16 and 13±11 ng/mL; p=0.001) among control, paroxysmal and persistent AF groups, respectively; 2) sex differences regarding inflammatory profile, oxidative stress and autonomic indirect markers in AF; 3) a prominent role of adipokines to discriminate AF recurrence after ablation. In persistent AF, FABP4 was the best predictor (LR coefficient 1.067, 95% CI 1–1.14, p=0.046).

Conclusion

The major finding of the present study is the sex differences of FABP4 and leptin according to AF burden. The relationship of these adipokines with oxidative stress, inflammatory and autonomic indirect markers might explain part of the mechanisms underlying the AF perpetuation.

Adipokines regarding Gender & AF burden

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Institute of Health Carlos III